def fibonacci(n):
    if n <= 0:
        return "请输入正整数"
    elif n == 1:
        return 0
    elif n == 2:
        return 1
    else:
        fib_list = [1, 1]
        for i in range(2, n):
            fib_list.append(fib_list[-1] + fib_list[-2])
        return fib_list[-1]

# 示例用法
n = int(input("Please a positive integer:"))
result = fibonacci(n)
print(f"{result}")